Hearing assistance devices include a variety of ear-level devices that assist or aid hearing of a wearer. Such apparatus may be worn partially or fully on the ear and/or in the ear. In the example of apparatus worn at least partially in the ear, the device must either employ a standard fit component that typically comes in a predetermined range of suitable sizes or it must be custom fit to the ear canal of the wearer. Devices requiring an accurate and close fit are typically custom fitted to the wearer's ear or ear canal. Such devices include completely-in-the canal (CIC) hearing aids, which are shaped to fit a particular wearer's ear canal. However, there are a number of devices that may benefit from custom fitting to match the geometry of the ear canal other than CIC hearing aids.
One disadvantage of making custom fitted devices is the use of reverse casting technique, in which an ear impression or earmold of a wearer is sent to a manufacturer and processed to construct the custom-fitted housing of the device. For example, the ear impressions must be made, sent to a facility, and processed at the manufacturer to create the custom fitted piece. This can add delays and require repeated office visits which are also time consuming and costly. It can also require one or more specially trained professionals, further increasing the cost.